2 Indications and current treatments
2.1 Barrett's oesophagus is a precancerous condition characterised by abnormal replacement of the squamous epithelium of the lower oesophagus by a type of columnar epithelium resembling that in the stomach and intestine.
2.2 In some patients, Barrett's oesophagus may progress through a series of stages to oesophageal adenocarcinoma – a cancer with a poor prognosis. These intermediate stages are graded into low‑grade and high‑grade dysplasia according to the degree of abnormal cellular architecture.
2.3 The risk of progression to oesophageal adenocarcinoma for anyone with Barrett's oesophagus is difficult to predict accurately. In general, the risk of cancer is highest for patients with high‑grade dysplasia, lower for patients with low‑grade dysplasia, and lowest for patients with no dysplasia (also referred to as 'intestinal metaplasia' – a change from epithelium that is normal for this site but with no evidence of dysplasia). Accurate classification of Barrett's oesophagus into these distinct histopathological types is difficult; there is the possibility of diagnostic misclassification because of biopsy sampling error and subjective biopsy interpretation. Strategies for addressing this include multiple biopsy sampling, diagnosis on at least 2 occasions, confirmation by 2 specialist histopathological experts and confirmation by an independent pathologist external to the original institution each time – all in the context of a multidisciplinary team.
2.4 The main risk factor for developing Barrett's oesophagus is a history of reflux of acid and/or bile into the oesophagus. Reflux commonly produces symptoms of heartburn but it can be asymptomatic.
2.5 The management of Barrett's oesophagus is determined by the dysplasia status. In Barrett's oesophagus with no dysplasia or low‑grade dysplasia, periodic endoscopic surveillance and repeat biopsies may be considered with the aim of early detection of progression to high‑grade dysplasia or cancer. If high‑grade dysplasia or early cancer (carcinoma in situ) is detected, then treatment is recommended. If the disease is superficial (confined to the mucosa), treatment can usually be done endoscopically.
2.6 Endoscopic treatments for Barrett's oesophagus aim to destroy the Barrett's epithelium, leaving a surface that is subsequently replaced with a normal squamous epithelium. If the Barrett's epithelium is flat, then it can be ablated using one of several possible modalities such as photodynamic therapy, argon plasma coagulation, laser ablation, cryotherapy or multipolar electrocoagulation. If there are visible abnormalities, such as nodules or ulcers, then those areas are usually removed by endoscopic resection.